Ben Kingsley stars again as Trevor Slattery, his character from "Iron Man 3," in the Marvel Studios short film "All Hail the King." / Marvel Studios

by Brian Truitt, USA TODAY

by Brian Truitt, USA TODAY

When filming a Marvel Studios short film starring his Iron Man 3 faux villain, Trevor Slattery, the 70-year-old knighted actor didn't want to come out of character to do an interview for a studio press kit.

Kingsley was having way too much fun living the nutty life of the eccentric Liverpudlian actor who fooled everybody, even Iron Man (Robert Downey Jr.).

"I realized I really enjoy playing this total odd concoction of a survivor, a great opportunist and, when you think about it, not a bad actor," says Kingsley. He revisits Trevor for All Hail the King, a 15-minute Marvel One-Shot featured on the Thor: The Dark World Blu-ray/DVD release (out Feb. 25).

For the first half of Iron Man 3, the second-highest grossing movie ($409 million) of 2013, Kingsley was threatening the world - and the well-being of Downey's Tony Stark - as the mysterious terrorist The Mandarin.

Then came the twist that split the comic-book fans in the crowd: Instead of being the longtime Marvel supervillain, the Mandarin was revealed as Trevor, a whacked-out British actor who was simply the hired front for the machinations of mad scientist Aldrich Killian (Guy Pearce).

Trevor was much more interested in soccer, sex and drugs than ruling the world, yet he still ended up in jail, which is where All Hail the King finds him. In an epilogue, a journalist (Scoot McNairy) comes to Seagate Prison to document Trevor's life story and reasoning for his actions.

"The worst aspects are the most endearing aspects of Trevor: his vanity, his narcissism, his pomposity, his total indifference to the real world around him. They all come out in this extraordinary interview," says Kingsley, 70.

All Hail the King allows him to play variations in character, just as he did in Iron Man 3. There is a flashback sequence to when Trevor played a Russian super-spy, which finds Kingsley sporting a flowing brown wig, thick mustache and what looks like one of Don Johnson's white Miami Vice suits. Kingsley also gets to whip out his best Sean Connery impression, which he improvised over the three-day short-film shoot.

Writer-director Drew Pearce "chose all the illogical takes that didn't make any sense and put them together," Kingsley says, "and there's Trevor."

Pearce can imagine an alternate reality where Kingsley's award-winning career took a few different turns and he could have been Trevor.

"He definitely wouldn't be a sir and he'd probably be living in a bedsit (boarding house) in West Kensington with two other old actors," Pearce says, laughing.

"The idea that we Trojan Horsed that into a superhero blockbuster is both ridiculous and also quite exciting."

Pearce was one of the guys responsible for the big Mandarin reveal: He co-wrote the Iron Man 3 screenplay with director Shane Black. He recalls the first day of movie press last spring in London when Kingsley approached Pearce and was worried he wouldn't be able to keep the Mandarin/Trevor switch a surprise.

"I told him, 'Sir Ben, you're one of the best actors of your generation. I suspect you'll be absolutely fine to pull this off,' " Pearce says.

But there are still questions to be answered in All Hail the King: Is he actually the Mandarin, with one more trick to pull on the world? And if Trevor wasn't the multi-ringed bad guy, who is?

Trevor is faced with certain doom, though, and the way Kingsley plays it, the jailed actor still doesn't quite know what's real and what's a performance.

"It's cunning," Kingsley says. "We don't know whether Trevor's mask to survive through life is 'I'm just a stupid, beer-drinking drug addict from Liverpool.' But inside there, there must be something going on to create the character that terrified Tony Stark and the world.

"He's not easy to quantify, and I don't now what surprises - if any - Trevor has up his sleeve,'' adds Kingsley. "But I love playing the complexity and the complete unpredictability."